Electric machines with a rotor and a stator can be used both as generators for generating power and as drive motors. If such an electric machine is not handled properly, being subjected to an impact or fall onto its front face, the relatively heavy deadweight of the rotor can result in irreversible damage. It is thereby irrelevant whether the machine is put down abruptly or falls from a low height for example. If a bearing bracket or the shaft is affected, damage is inevitable, generally to the bearings. A further cause of damage is incorrect transportation, in particular in the case of machines transported with the shaft disposed in a vertical manner. Such transport damage occurs in particular due to holes in the road surface or as a result of rail joints. Finally fast axial acceleration can cause serious damage when the machine is in use. This is the case particularly when the electric machine is used as a drive in the automotive field.
The damage produced by the causes mentioned above is extremely difficult to identify. This means that in the case of transportation or handling damage in particular machines with damaged bearings can still be supplied for their intended use. This often then results in premature failure of the machines.
The problems mentioned above can be prevented for example by particular care when handling machines. This means that special work instructions have to be issued or further measures have to be implemented, for example employee training. It is known that suitable packing can be used to prevent transportation damage. The risk due to fast axial acceleration, in the automotive field in particular, can be compensated for to some degree by the mounting position of the electric machine.